WDPN32 PGTW 210300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (FUNG-WONG) WARNING NR 15// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 16W (FUNG-WONG), LOCATED APPROXIMATELY 209 NM SOUTH-SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHEASTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS THE LOW LEVEL CIRCULATION HAS BECOME PARTIALLY EXPOSED AS THE SYSTEM MAINTAINED OVERALL WRAP AND CONVECTIVE DEPTH AS IT APPROACHES TAIWAN. THE INITIAL POSITION IS BASED ON A MICROWAVE EYE FEATURE ON A 202220Z 37 GHZ SSMIS PASS. THE INITIAL INTENSITY IS BASED ON CONGRUENT DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD. UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM IS UNDER THE RIDGE AXIS IN AN AREA WITH LOW (05 TO 10 KNOT) VERTICAL WIND SHEAR (VWS) AND STRONG EQUATORWARD OUTFLOW, AS EVIDENT ON WATER VAPOR IMAGERY. TS 16W IS CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) TO THE EAST. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS FUNG-WONG IS FORECAST TO TRACK NORTH-NORTHEASTWARD OVER THE NEXT 12 HOURS UNDER THE STEERING INFLUENCE OF THE STR AS IT DRAGS ACROSS WESTERN TAIWAN. AFTERWARDS, THE STR WILL BUILD AND CAUSE THE CYCLONE TO TRACK MORE NORTHWARD TOWARD THE CHINESE EASTERN SEABOARD. FAVORABLE UPPER LEVEL CONDITIONS ARE EXPECTED TO PERSIST OVER THE NEXT 12 HOURS, HOWEVER, INTERACTION WITH THE RUGGED TERRAIN OF TAIWAN, AND LATER ON WITH THE CHINESE COAST, IN ADDITION TO INCREASING VWS, WILL ERODE AND EVENTUALLY DISSIPATE THE SYSTEM BY THE END OF THE FORECAST PERIOD JUST SOUTH OF SHANGHAI. AVAILABLE MODEL GUIDANCE REMAINS IN FAIRLY TIGHT AGREEMENT LENDING HIGH CONFIDENCE TO THE JTWC FORECAST.// NNNN